Tissue Acquisition and Specimen Processing in the Diagnosis of NSCLC

The current management of non-small cell lung cancer (NSCLC) requires pathological differentiation between adenocarcinoma and squamous cell carcinoma using immunohistochemistry and morphological analysis. Additionally, as novel therapies for specific genetic mutation and chromosomal rearrangement profiles in patients with adenocarcinoma are becoming more numerous and clinically available, adequate tissue acquisition and specimen processing have become crucial. Historically, tissue was obtained via mediastinoscopy or video-assisted thoracoscopy (VATS). However, 80% of patients with lung cancer are ultimately found to be nonsurgical candidates. More recently, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been shown to be a safe and potentially superior modality to obtain tissue for diagnosis, staging, and molecular profiling. The preparation of tissue specimens has also been the subject of study as different methods have been shown to increase cellular yield. This is of particular importance as the number of clinically significant targetable mutations and chromosomal rearrangements continues to grow and the need for more tissue increases.